Dyeing animal fibers



-Patented Mu; 28, 1933 UNITED STATES PATENT OFFICE- ALFBED FISOHESSER, F mNKIOBT-OH-TEE-m-FEGHENEEEE, GERMANY, AS

SIGN'OB TO GENERAL ANILINE WORKS, INC., 0! NEW YORK,

OF DELAWARE N. Y... A. oonroaa'non nxnnm ANIMAL manna Ho Drawing. Application In accordance with the present invention leuco-ester salts of vat dyestufis can be fixed on the animal fiber also in an alkaline medium in the presence of a reducing agent.

It is a surprising fact that this process does not require an elevated temperature but takes place already at room temperature. In comparison with the hitherto usual dyeing processes it shows several important advantages. It allows mixed shades to be produced easily by suitable combinations. Furthermore, the material can be partially coated with fat, wax or other mechanical resist which in consequence of the low temperature prevailing sufiiers no injury lowing fixation of the ester-salt. In this manner white and colored batic-efiects are produced on a colored. ground and exhibit a clearness and beauty hitherto not obtainable by means of leuco-ester salts of vat dyestufis.

The present process may also be applied to mixed fabrics containing animal fibers.

In order to further illustrate my invention the following examples are given, the parts being by weight and all temperatures in centigrade degrees, but it is however to be understood, that my invention is not limited to the particular products nor reacting con- 40 ditions mentioned therein Ewample 1 Bleached wool is partially coated with one of the customary wax resists (for instance during the fola med August 4, 1980, Serial No. 478,124, and in Germany September a, 1929.

beeswax) and then treated with the follow ing mixture: r

10 parts of the sulfuric acid ester-salt of leuco-5.7.5-trichloro-indigo, 950 parts of lukewarm water,

10 parts of ethylene-thiodiglycol,

10 parts of the sodium salt of benzylsulfanilic acid,

10 parts of potassium carbonate,

10 parts of formaldehyde-sulfoxylate (which may be replaced by hydrosulfite) 1000 parts.

After hanging in the cold for about one hour, the goods are washed with water and developed at about 35 in a bath containing 20 parts of potassium persulfate and 37 parts of 66 B. sulfuric acid in 1000 parts of water. Then they are washed and dried. Thereafter the wax is removed for instance by treating with benzine or benzene. The goods are advantageously again warm soaped and washed. In this manner white effects on a violet groundation are obtained.

Example 2 I and yellow.

Emample 3 A fabric containing wool or'silli is d ed 1n thecustomary manner light or mi dle mixed shades the pure shade of the dyestuff used for the cross dyeing is obtained.

Example 4 W001 or silk is dyed in the manner described in Example 1 with the employment of the ester salt of 6.6 -diethoxy-indigo, whereby white effects on orange are obtained. Then the goods are cross dyed with any wool dyestufi. Besides the pure colored efiect produced by the cross dyeing matter a mixed dyeing of both dyestuffs is obtained.

Example 5 Weighted or unweighted silk is treated according to Example 1 with a leuco-ester salt. The developing bath is replaced by a bath containing 1-2 parts of potassium chromate and 18 parts of sulfuric acid in 1000 parts of water.

Example 6 Bleached wool or weighted or unweighted silk is printed on a cylinder printing machine provided with engraved heatable rollers with the following resist:

50 parts of beeswax, 650 parts of colophony, 30 parts of spermaceti,

15 parts of molten mutton tallow, 25 parts of parafiine, 230 parts of oil of turpentine,

1000 parts.

The goods are further treated according to Example 1.

Example 7 Example 8 Spun or woven dye goods (unweighted or weighted silk or chlorinated wool) are previously treated in a manner suitable for the printing process and advantageously printed with a wax resist. Then they are treated.

cold or lukewarm for one hour in the following bath:

10 parts of the sulfuric acid ester salt of leuco-6.6-diethoxy-indi o, 10 parts of formaldehyde-su foxylate, 20 parts of triethanol-amine, 960 parts of water,

1000 parts.

The dyeing is developed with one of the oxidizingbaths mentioned in Examples 1 and 5.

Example .9

The rocess is carried out as described in Examp e 8, but the dye-path is replaced by the following one:

5 parts of the sulfuric acid ester salt of leuco-5.7.5s-trichloro-indigo, 955 parts of water,

10 parts of formaldehyde-sulfoxylate, 20 parts of triethanol-amine, 10 parts of sodium nitrite,

1000 parts.

The dyeing is developed in an acid bath whereto persulfate or chromate may be admixed.

I claim:

1. Process which comprises dyeing animal fibers in the cold with a bath containing sulfuric acid ester salts of leuco compounds of vat d estuffs, an alkali of the group consisting 0 alkali metal carbonates and triethanolamine and reducing agents and developing the dyeing with a bath containing an acid and oxidizing agents of the group consisting of persulfate and chromate.

2. Process which comprises dyeing animal fibers, which are previously dyed and partially coated with a wax-resist, in the cold with a bath containing sulfuric acid ester salts of leuco compounds of vat dyestufi's, an alkali of the group consisting of alkali metal carbonates and triethanol-amine and formaldehyde sulfoxylate and developing the dyeing with a bath containing an acid and oxidizing agents of the group consisting of persulfate and chromate.

3. Process which comprises dyeing animal fibers, which arepreviously dyed and partially coated with a wax-resist, in the cold with a bath containing sulfuric acid ester salts of leuco compounds of vat dyestuffs, an alkali of the group consisting of alkali metal carbonates and triethanol-amine, reducing agents and nitrite and developing the dyeing with a bath containing an acid and oxidizing agents of the group consisting of persulfate and chromate.

In testimony whereof, I aflix my signature.

' ALFRED FISCHESSER. 

